Lateral Wall of the Cavuni Nasi in Man. ' 671 



EXPLANATION OF FIGURES 



Figs. 3S, 39, 40 Drawings from dissections of specimens from the anatomical 

 series, Cornell University. The dissections have been made with special refer- 

 ence to the furrows and folds on the lateral surface of the frontal recess, and the 

 buUar folds on the lateral wall of the descending ramus of the meatus medius. 

 The specimens are from term fetuses. 



Fig. 38 (X 1.8) The concha media has been partly cut away so as to expose the 

 frontal recess and its structures and the bullar folds and furrows. The processus 

 uncinatus has also been partly cut away so as to get a better exposure of the bul- 

 lar folds and the primitive sinus maxillaris. 



Fig. 39 (X 1.2) The concha media has been partly cut away thus securing a 

 good exposure of the frontal recess with its folds and furrows, and the folds and 

 furrows of the bulla ethmoidalis. The infundibular fold is also well shown in the 

 drawing. 



Fig. 40 (X 1.2) . Especially note the frontal recess and the low degree of differ- 

 entiation of frontal folds as compared with the specimens represented in figs. 

 38 and 39. The processus uncinatus is too large to allow the inferior bullar fold 

 to be seen. Portions of the concha media and superior have been cut away. 



Figs. 41, 42, 43 Drawings from dissections of specimens from the anatomical 

 series, Cornell University. The dissections have been made with especial refer- 

 ence to the ascending and descending rami of the meatus medius. The concha 

 media is partly cut away in all the specimens. 



Fig. 41 (X 1.2) Shows the well formed frontal folds (conchae) and furrows on 

 the lateral wall of the frontal recess, also the accessory concha of the meatus 

 superior. From a term fetus. 



Fig. 42 (X 1.2) Note the manner of pouching of the frontal furrows and the 

 frontal recess in the formation of anterior ethmoidal cells and the frontal sinus; 

 also the developing sinus sphenoidalis. This specimen was from a child aged 

 approximately five months. 



Fig. 43 (X .6) In this specimen there were apparently no frontal folds nor 

 furrows, or they were early obliterated. It will be noticed that the frontal recess 

 is expanding towards the frontal region in the establishment of the frontal sinus. 

 Note also the multiple ethmoid-cell anlages in the region of the suprabuUar fur- 

 row. From a child aged approximately fourteen months. 



